Shelly 1L, switching logic

Hardware
1

Hello,

Shelly offers 1L no neutral switch turning conventional switches into smart ones. Here is the wiring diagram:

Shelly 1L wiring

My demand is to have control through both WiFi and key switch. In case if control system is down, manual control has to work. I wonder which switching logic Shelly 1L has.

What happens if:

  • An 1L switch is turned on over WiFi and after it key switch circuit connected to SW1/2->Sx is closed/breaked;
  • An 1L switch is turned off over WiFi and after it key switch circuit connected to SW1/2->Sx is closed/breaked.

What is bypass needed for in case of no neutral wiring?

Regards

2

Because there is still some current needed to power the device.

3

Thank you. This is only applicable for loads with overall power less than 20W, correct?

4

Can’t hurt to always install it. What if you change bulbs ?

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5

image

You would normally install the Shelly 1L behind an existing wall switch and connect the switch to SW1 as per your diagram above. I have the Shelly 1L’s configured so that any change in the switch state toggles the light as shown below (from the Shelly Web UI).

image
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This means that you can still manually toggle the light even when WiFi or HA is down.

If you have a double switch then you can wire the second switch to SW2 and use this to control other things in HA via Automations.

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